1) Field of the Invention
The present invention relates generally to agricultural seeding implements having a plurality of metering devices, such as grain drills or the like, and more specifically to a metering control system for such an implement.
2) Related Art
Grain drills typically include a plurality of transversely spaced seed meters with fluted feed wheels driven from a ground wheel for metering seed at a rate proportional to the forward speed of the implement. Changing the seeding rate usually involves either adjusting the ratio of a transmission located between the ground wheel and a drive shaft connected to the fluted feed wheels, or moving the fluted feed wheels within the meter housings by shifting the drive shaft transversely to adjust the effective metering area of the wheels. Gross adjustments to modify, for example, the metering for different types of seeds are usually accomplished by altering a seed gate position and/or changing the transmission speed ratio.
Heretofore it has been difficult for the operator to know the exact seeding rate and to fine-tune the adjustment when moving to a new field or when changing seed varieties, and it has been virtually impossible to change the seeding rate on-the-go for varying conditions. Existing monitor systems to check seeding rate are expensive (especially when each seed row must be equipped with a monitor similar to the arrangements utilized with row crop planters), and providing an effective and affordable controlled or closed loop system for a grain drill has continued to be a problem.